Automatic amperage feed control mechanism



Aug. 18, 1936. c. J. HEss 2,051,445

AUTOMATIC A'IPERAGE FEED CONTROL MECHANISM FiledvJune 16, 1934 2 Sheets-Sheet l ffy. 1.

I n f/ hun Aug. 1s, 1936. l C. J, HESS 2,051,445

- AUTOMATIC AMPERAGE FEED CONTROL MECHANISM Filed June 16, 1934 2 sheets-sheet 2 Patented Aug. 18, 1936 PATENT OFFICE AUTOMATIC AMPERAGE FEED CONTROL MEcnANrsM Clarence J. Hess, Shade Gap, Pa. Application June 16, 1934, Serial No. 231,002 9 Claims. (Cl. 172-239) This invention relates to feed control mechanism, and more particularly to a device for controlling the rate of feed to a mill such as a flour or feed mill or the like.

One object of the invention is to provide a device for controlling the rate of feed in accordance with the load upon the mill.

Another object of the invention resides in a device for preventing initiation of the feed until the mill is brought up to speed. t

Another object of the invention is to provide an electrically driven mill and feed mechanism,

in which the rate of feed is automatically controlled in accordance with the electrical load taken by the driving motor.

Another object of the invention is to provide a feed control mechanism for maintaining the load current taken by the mill driving motor substantially constant by regulating the rate of feed.

Another obj ect of the invention is to provide a device for automatically and immediately stopping the feeding mechanism ,whenever the mill driving motor is disconnected from its source of power.

A further object of the invention is to provide a time delay device to initiate the operation of the feeding mechanism at a predetermined time after the mill driving motor has been connected to its source of power.

A still further object of the invention is to provide a friction clutch between a driving motor and the feed mechanism and electrically actuated means responsive to the load on the mill for causing the clutch to slip in the event of an overload.

Other objects and advantages of the invention will appear in the following description of the preferred embodiment of the invention shown in the attached drawings, of which:

Figure l is a plan view of the clutch mechanism;

Figure 2 is a plan view of the clutch mechanism with the top cover and solenoid brake mechanism removed;

Figure 3 is a vertical cross section taken on lines 3-3 of Fig. l;

Figure 4 is schematic diagram of the electrical connections and apparatus;

Figure 5 is a detail of a clutch shifter lever;

Figure 6 is a detail view in vertical section of the clutch shifter lever bearing;

Figure 'l is an elevation of the solenoid operated brake mechanism; and

Figure 8 is a detail of one of the gears of the clutch mechanism on a reduced scale.

Referring'more particularly to the drawings, I indicates the clutch mechanism housing which comprises a base member II and a cover member I2. The base member II is provided with four half bearings I3 to receive a pair of shafts I 4 and I5 extending laterally through the housing. Similarly the cover member I2 is pro vided with half bearings I6 which cooperate with the half bearings I3 to form journals for the shafts I4 and I5 whenlthe cover I2 is in position. Shaft I4 is provided with a gear Il loosely journalled upon the shaft I4 between a friction clutch disc I8 rigidly mounted upon the shaft 15 I4 and a friction clutch disc I 9 mounted upon the shaft lil so as to be slidable axially thereof. The clutch disc I9 is provided with a hub portion 2D which is caused to rotate with the shaft by means of a key 2I. Also the shaft I4 may 'be provided with a thrust collar 22 fixed thereto to prevent longitudinal movement thereof. It will be seen that forcing the disc I9 axially of the shaft I4 against the gear Il Will cause the said gear to be frictionally engaged between the discs I8 and I9 so as to rotate with the shaft It.

The shaft I5 is also provided with a gear 23 which meshes with the gear Il' and which is positioned between friction clutch discs 2li and 25 which are exactly similar to the discs I8 and I9 upon the shaft I4, and are similarly mounted upon the shaft I5. The shaft I5 may also be provided with a thrust collar 22 exactly similar to the thrust collar upon the shaft I4. gears I1 and 23 and the clutch discs I8, I9, 24 and 25 run in oil contained in the housing I0 and as shown in Fig. 8, the gear I1 is provided with curved slots 25a cut entirely through the gear and extending outwardly from a point adjacent the center of the gear beyond the outer peripheries of the clutch discs I8 and I9 as shown in Fig. 3. The slots 25a pick up oil from the housing I0 and deliver it to the friction surfaces between the gear I'I and the discs I8 and I9. The gear 23 is also provided with similar slots (not shown) for the purpose of supplying oil to the friction surfaces between the gear 23 and clutch discs 24 and 25.

The two clutch discs I9 and 25 are shifted to engage and disengage the gears Il and 23 respectively by a solenoid 26 mounted upon a bracket 21 carried by the cover member I2. The plunger 28 influenced by the solenoid 26 is provided with a rod 29 extending through an aperture 30 in the upper end ofl a shifter lever 3| extending downwardly through the cover member i2 and journaileol at 32 in said cover member. As shown in Figure 5, the shifter lever 3l is provided with a pivot 3s extending therethrough which is positioned in the bearing il?! formed partly in the cover member S2 and a bearing plate 35 bolted thereto. The lower end of the shifter lever 3i terminates in a fork e@ provided with lugs 3l which engage an annular groove 38 in the hub 29 of clutch. disc i9.

The solenoid plunger rod 29 is provided with a collar 38a fixed thereto which bears against one side of the shifter lever 3|. A compression spring 39 is positioned between the collar 39u, and a washer 40 carried by the solenoid bracket 21. The solenoid plunger rod 29 also extends through! an aperture 4| in a rocker lever B2 journalled at 43 upon the top surface of the cover member 2. A compression spring @te is positioned between the shifter lever 3l and 'the rocker lever 42 AA nut 95 is screw threaded upon the extreme end of the solenoid plunger rod 29 to maintain said springs under compression.

The clutch disc 25 is also actuated by a shifter lever 56 (Fig. 1) provided with lugs 31 engaging an annularl groove 5l (Fig. 2) upon the hub of the clutch disc 25. A shifter rod 5l' extends through an aperture in the upper end of the shifter lever 55, through an aperture in a stationary abutment 50 upon the upper surface of the cover member i2 and an aperture in the end of the rocker lever i2 remote frein the solenoid plunger rod 29. A compression spring 59 is positioned between the shifter lever 56 and the abutment 59. The shifter rod 51 is provided with an adjusting nut 60 screw-threaded upon .one end thereof to be engaged by the rocker 42 during the operation of the device.

The shafts I4 and I5 extend beyond one side of the clutch mechanism housing l0 and are provided with pulleys 6| and 62. The shaft i5 is also extended outwardly from the other side of the clutch mechanism housing i0 and is provided with a brake drum 63 to receive a solenoid operated brake more clearly shown in Figs. 1 and 7. The brake includes a brake band 64 resiliently secured to a bracket 65 secured to the base member I I of the clutch mechanism housing. A spring 66 carried by an operating rod' 61 extending through brackets 58 and 69` carried by the opposed ends of the brake band 54 urges the brake band toward tightened position. The brake is released by a solenoid 10 mounted upon the bracket 65 by means of a bell crank 1| journalled in the bracket 68 and connected to the bracket 69 by compression links 12.

The operation of the device thus far will now be described. The clutch disc I9 is normally held in disengaged position by means of the spring 39 operating through the shifter lever 3|. The clutch disc 25 is normally held in engaged position by means of the spring 59 operating through the shifter lever 56. tion of the solenoid 28 the solenoid plunger 28 is pulled to the left in Fig. 3 to compress the spring 39 and rock the shifter lever 3| anticlockwise in Fig. 3 through spring 44. The spring 44 is of greater strength than the spring 39 but is normally prevented from maintaining the clutch disc I9 in engaged position by reason of the collar 38a fixed upon the solenoid plunger rod 29. This movement of the solenoid plunger rod 29 rocks the rocker lever 42 about its pivot Upon energiza- A anche d5 in a clockwise direction in Fig. i to bring the opposite end oi the rocher lever 32 adjacent the nut @il upon the shifter rod 5l. The engagement of clutch disc i9 with the gear ii prevents further movement thereof. Further 5 movement oi the solenoid plunger 29 toward the left in. Fig. 3 by reason of an increase in the energization of the solenoid 2t acts to compress the spring 44 and further rock the lever d2 in a clockwise direction in Fig. 1. The lever 82 lo engages the nut( 69 upon the shifter rod 5l to compress the spring 59 and rock the shifter lever 5S to allow slipping between the clutch disc 25 and the gear 23. It will thus be seen that energization of the solenoid 26 first causes l5 the engagement of the clutch disc i9 with the gear i1 and that further energization. of the solenoid 26 will cause slipping between the clutch disc 25 and the gear 23.

In Fig. 4 is shown a schematic diagram of 20 the electrical apparatus which operates the various clutches and solenoid brake heretofore described. In this ligure a main motor 'i3 drives a mill such as a iiour or feed mill (not shown) by means of the belt i4 and is connected to a 25 source of electrical power 'i5 through a manually operable switch or starter i6. A feed motor i1 drives the shaft i4 of the clutch mechanism through a belt 18 and a feed mechanism (not shown) is driven by a belt i9 engaging pulley 62 mounted upon shaft l5.

The motors i3 and 11 are connected through the switch 16 to the line 15 by conductors 80, ti and 82, and may operate upon either alterhating or direct current. lZihe conductor 82 is connected to the switch 16 by conductors 83 and t4 through an automatic feed control solenoid 85. Although two motors are shown, it is obvious that both the mill and the feed mechanism may be driven from a single motor if the arrangement of these machines is such as to make this practical. A contact making .voltmeter 86 provided with a dash-pot 81 is connected across conductors and 82 and is provided with a moving contact 88 and a stationary contact 89 45 to close a circuit through a relay 90 also connected across conductors 80 and 82 in series with contacts 88 and 89 so as to cause the relay 90 to operate after a time delay. Energization of the relay 90 closes contacts 9| and 92 thereof to connect the clutch operating solenoid 26 and the brake operating solenoid 10 in parallel with automatic feed control solenoid 85 and in series with the manually operable rheostat 94 and the automatic control rheostat 95. This circuit may be traced from conductor 83, through manually operable rheostat 94, automatic control rheostat 95, contacts 9| and 92 of the relay 90 through solenoids 26 and 10 in parallel and back to conductor 84. The rheostat 94 may be operated manually to control the amount of current flowing through clutch operating solenoid 26 and brake operating solenoid 10 and a. further automatic control of this current is provided by the rheostat 95 operated by the solenoid 85 by means 65 of a solenoid plunger 91 pivotally connected at 98 to a contact lever 99 which is pivoted at |00. The solenoid plunger91 is provided with a dashpot 0| and the contact lever 99 is returned by a. spring |02. An adjustable stop which may be an adjusting screw |03 screw-threaded through a stationary member |04 and bearing against the contact lever 99 serves to adjustably limit the upward movement of the contact lever 99.

In the operation of the device, when the switch 75 Il is closed, the motors '13 and I1 start but since the clutch disc -I9 is disengaged'from the gear Il the feed mechanism is not driven while the motors are coming up to speed. ,This is true since .the relay 90 is open and the solenoid-26 is not energized. Also when the switchen is closed,

voltage is impressed across the contact-making voltmeter 96. The, contacts 08 and 89, however, are not closed until after, a time delay because of the dash-pot 81.. In practice the dash-pot 81 is adjusted so that the contacts 88 and 89 are not closed until the mill motor I3 has come up to speed. `As soon as contacts 98 and 89 are closed by `the contact-making voltmeter 86, relay 90 is energized to close contacts 9| and 92 to energize clutch operating solenoid 26 through the manually operable rheostat 9| and the automatically operable rheostat 95. At this time the load current on the motor .13 has reached or is less than its normal operating value depending v upon the amount of material in the mill and in operation the rheostat 94 is adjusted so that sufflcient current flows through the solenoid 26 to engage clutch disc I9 with the gear I1 and slight slipping of the gear 23 relative to clutch disc 25. f

Also when contacts 9| and 92 are closed brake operating solenoid I0 is energized to release the brake 64 and upon engagement of clutch disc I9 with gear II the feed mechanism is driven by belt 19 through clutch gear 23 and clutch discs 24 and 25. At this stage both the mill and the feed mechanism are being driven at their normal speeds. If the load current of the motorl 13 increases above the normal value due to too much material in the mill or other causes, the current through clutch solenoid 26, which is connected in series with the motor 13 and in parallel with automatic control solenoid 85. increases to disengage clutch disc 25 from gear 23 tol a greater extent to allow the feed mechanism to slow down or even stop. The current through clutch solenoid 26 is prevented from increasingas fast as the motor current by the automatic control rheostat 95 which is operated to cut in resistance by the automatic control solenoid 85 when the motor current increases. When the load current on motor 13 again drops toward normal value, the current through clutch solenoid 26 decreases to allow tighter engagement of clutch disc 25 with gear 23 to again drive the feed at normal speed. The decrease in current through solenoid 26 is partially compensated by the operation of automatic control solenoid 85 operating to cut out resistance in rheostat 95. Thus the control solenoid 85, in conjunction with clutch solenoid 26, is effective to maintain the load current on the motor 'I3 at a predetermined value as shown by the ammeter 93. The desired predetermined value of load current on'motor 13 may be selected by adjusting manually operable rheostat 94 to adjust the amount of current flowing through clutch operating solenoid 26.

.current as clutch operating solenoid 26 but the .:aid mill, means fordriving a feed mechanism 'I'he adjustable stop screw |03 bearing against contact lever 99 determines l 3 power fails for any other *.reason, the contacts 88 and 89 lof the .voltmeter 99 immediately disengage. which permits contacts 9| and 92 of the relay 99 to dlsengage, the clutch operating solenoid 25 and the brake operating solenoid .10 5 are immediately deenergized to disengage clutch i A disc I9 and gear I'l and the. feed is immediately stopped by the brake 64. The brake operating solenoid 'Iis subjected to the same variations in current through solenoid l0 is always suilicient to maintain the brake released when contacts 9| and 92 are closed'. While I have herein disclosed the preferred embodiment of my invention, it is to be underl5 stood that the precise structure disclosed may be modied within the scope of the appended claims.

Having thus described my invention, I claim: 1. In a device forcontrolling the rate of feed 20 toa mill or the like, an electric motor for driving said mill, means fordriving a feed mechanism for feeding material to said mill, a friction clutch mechanism between said means and said feed mechanism, saidI means being disconnected from 25 said feed mechanism by said clutch mechanism when said motor is not connected to a source of power, means for connecting said motor to said source of power, means for operating said clutch mechanism to cause said driving means to drive said feed mechanism after said motor has been -the rate of feed when said load increases and to 35 increase the rate `of feed when said load decreases.

2. Inv a device for controlling the rate of feed to a mill or the like, an electric motor for driving for feeding material to said mill, a friction clutch mechanism between said means and said feed mechanism, said means being disconnected from said feed mechanism by said clutch mechanism when said motor is not connected to a source of power means for connecting said motor to said source of power, electrical means for operating said clutch mechanism to cause said driving means to drive said feed mechanism after said motor has been connected to said source of power vand electrical means responsive to the load current taken by said motor for causing operationv yof said clutch mechanismvto decrease the rate of feed when said load increases and to increase the rate of feed when said lcad decreases.

3. In a device for controlling the rate of feed yto a mill or the like, an electric motor for driving said mill, means-for driving a feed mechanism for feeding material to said mill, a friction clutch mechanism between said means and said G0 feed mechanism, said means being disconnected from said feed mechanism by said clutch mechanism when said motor is not connected to a source of power, means for connecting said motor to said source of power, electrical means for operating said clutch mechanism to cause said driving means to drive said feed mechanism, a time delay device for initiating the operation of said clutch operating means after said motor has been connected to 'said source of power and elec- 70 trical means responsive to the load current taken 'by said motor for causing operation of said clutch mechanism to decrease the rate of feed when said load increases and to increase the rate of feed when said load decreases. 75

4. A device vfor controlling the rate of feed to a mill driven by an electric' motor comprising, means for driving a feed mechanism for feeding material to said mil1,-a friction clutch mechanism between said nians and said feeding mech-` anism including a pair of clutches, means `for connecting said motor to a. source of power, one of said clutches being disengaged when said motor is disconnected from said source of power, and electrical means for engaging said last mentioned clutch after said motor is connected to said source of power, the other of said clutches being normally engaged, said electrical means including means responsive to the l'load current taken by said motor for causing at least partial disengagement of said other clutch when said load current exceeds a predetermined value.

5. A device for controlling the rate of feed to a mill driven by an electric motor comprising, means for driving a feed mechanism for feeding material to said mill, a friction clutch mechanism between said means and said feeding mechanism including a pair of clutches, means for connecting said motor to a source of power, one of said clutches being disengaged when said motor is disconnected from said source of power, electrical means for engaging said last mentioned clutch after said motor vis connected to said source of power, the other of said clutches being normally engaged, said electrical means being responsive to the load current taken by said motor for causing at least partial disengagement of said other clutch when said load current exceeds a predetermined value, and manually operable means for adjusting said predetermined value of load current.

6. In a device for controlling the rate of feed to a mill or the like, means for driving a feeding mechanism for feeding material to said mill, a friction clutch mechanism between said means and said feeding mechanism including a pair of friction clutches, one of said clutches being normally engaged and the other of said clutches being normally disengaged, a. single solenoid for operating both said clutches, means for energizing said solenoid for engaging said normally disengaged clutch and means for increasing the energization of said solenoid to at least partially disengage said normally engaged clutch.

7. In a device for controlling the rate of feed to a mill or the like having an electric motor driving a feeding mechanism for feeding material to said mill, said device comprisingV a pair of shafts, one of said shafts being driven by said feed mechanism driving means and having a gear loosely journalled thereon, the other of said shafts driving said feeding mechanism, and having a gear loosely journalled thereon and meshing with said rst named gear, independently operable clutches for clutching said gears to said shafts for rotation therewith, one of said clutches being normally engaged and the other of said clutches being normally disengaged, a single solenoid for operating both said clutches, means for connecting said motor to a source of electrical power, means including a 5 contact making voltmeter actuated by' the voltage impressed upon said motor and a tim; delay `device forenergizing said solenoid at a predetermined time after said motor is conne ted to said source of power to engage said normally 10 disengaging clutch, magnetically operated means responsive to the load current taken by said motor for increasing the energization of said solenoid to at least partially disengage said normally engaged clutch upon increase of said l5 load current above a predetermined value, manually controlled means for predetermining said value of said load current, means for returning said clutches to normal position when'said motor is disconnected from said source of power, means for applying a brake to the shaft driving said feeding mechanism when said motor is disconnected and means for releasing said brake when said motor is connected to said source of power.

8. In a device for controlling the rate of feed to a mill or the like driven by an electric motor, means for driving a feed mechanism for feeding material to said mill, solenoid operated means responsive to changes in load current to said motor for controllingsaid feed mechanism driving means to control rate of feed to said mill, a solenoid connected in series with said motor for operating said solenoid operated means, a variable resistance connected in series with said solenoid and an automatic control solenoid connected in series with said motor for varying said resistance to reduce the change in the current through said first named solenoid due to changes in said motor current.

9. In a device for controlling the rate of feed 40 to a mill or the like driven by an electric motor, means for driving a feed mechanism for feeding material to said mill, solenoid operated means for controlling said feedy mechanism driving means to control the rate of feed to said mill, a solenoid connected in series with said motor for operating said solenoid operated means to decrease said rate of feed upon an increase of motor current, a variable resistance connected in series with said solenoid, an automatic control solenoid for increasing the resistance of said variable resistance upon anincrease of motor current to partially prevent an increase in the current through said first named solenoid due to an increase in motor current and an adjustable means for preventing further operation of said automatic control solenoid to increase said resistance when said motor current reaches a predetermined maximum value.

CLARENCE J. HESS. 

